JP3382017B2 - Method and apparatus for transmitting and receiving program information - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program information transmission / reception system and its apparatus which are effective for digital television broadcasting in which a video signal is digitally compressed and transmitted.

[0002]

2. Description of the Related Art In recent years, along with the diversification of television broadcasting and the rapid progress of Japanese high-definition technology, next-generation TVs centered on terrestrial broadcasters in the US
The momentum for the development of ATV (Advanced TV), which is a broadcasting system, is increasing. In 1987, the FCC (American Federal Communications Commission) established an advisory committee and publicly called for ATV transmission systems from internal and external organizations. Among them, 4 systems using digital transmission systems remain as final candidates. Moreover, the four methods are being integrated into one.

Generally, when a video signal is digitized, the amount of information thereof becomes enormous, and it is difficult to directly transmit this information or store it in a recording medium. For example, the total data rate of the current 525, 2: 1 interlaced signal is 216 Mbps. Therefore, the video signal is compression-encoded using a composite of DCT (discrete cosine transform) processing, interframe predictive encoding, run-length encoding, entropy encoding, and the like. These image compression techniques utilize the spatial and temporal redundancy of the image signal to effectively reduce visually innocuous components, so that the original image can be completely restored by decoding. It ’s not possible, but MPE
In G2, the rate after compression is about 5 Mbps and the current N
It is said that the quality is comparable to TSC. Note that this value differs depending on the compression method.

One advantage of TV broadcasting in which a video signal is digitized and transmitted is that a plurality of programs can be transmitted in one transmission channel. A transmission channel is a channel used in current TV broadcasting and has a band of 6 MHz. According to Reference (1) "Nikkei Electronics Books, Data Compression Technology and Digital Modulation Technology", 4 bits (24 = 16 values) are assigned to one symbol when digital transmission is performed using general 16QAM modulation. Bits / second / Hz will be transmitted. Therefore, when 16QAM modulation is used in the current one terrestrial channel, it is possible to transmit at 6M × 4 = 24M / sec. However, the actual transmission rate is slightly lower than this due to the filter characteristic for preventing interference between adjacent channels and the overhead due to the error correction code.

On the other hand, the compressed video signal is 5 Mbps as described above, and the compressed audio signal is several hundred Kbps.
If it is a program such as a current TV, four programs can be simultaneously transmitted within one transmission channel.

Further, in addition to video and audio, it is possible to multiplex and transmit data for supplementing program contents and various data similar to character multiplex broadcasting. The method of multiplexing a plurality of programs will be described below in Reference (2) "INTERNATIONAL ORGA.
NIZATIONFOR STANDARDIZATION ORGANIZATION INTERNATI
ONALE DE NORMALISATION ISO / IEC JTC1 / SC29 / WG11 CODE
The description will be made according to the MPEG2 system layer described in "ING OF MOVING PICTURES AND ASSOCIATED AUDIO".

FIG. 7 is a diagram for explaining packetization required for multiplexing. In the figure, 201, 20
Reference numeral 2 is an original video signal and an original audio signal for one hour, respectively. Original video signal 201 is 216 Mbps, original audio signal 20
2 is 1.5 Mb of sound quality similar to CD (compact disc)
ps. First, each original signal is compressed to obtain compressed video data 203 and compressed audio data 204. At this point, the original video signal 201 of 216 Mbps becomes 5 Mbps,
The original audio signal 202 of 1.5 Mbps has a rate of 400 Kbps. In MPEG2, these are called elementary streams (hereinafter ES). Further, each ES is subdivided into a certain unit, and a packet is formed into a format in which a header is added to each unit. For example, in the case of a video signal, the compressed data 203 is converted into 1 frame units (203
a, 203b, 203c ...). Each corresponds to the original video signal 201a, 201b, 201c ..., The data amount of 201a to 201c is the same, but 2
Since 03a to 203c are variable-length coded, they generally have different data lengths. The data 203a to 203c subdivided in 1-frame units are packetized with packet headers 207a to 207c added thereto. For example, the packet 205a includes compressed image data 203a for one frame and its header 207a.
The header includes time stamp information necessary for decoding, packet length, and information indicating the data type. In MPEG2, this is called a packetized elementary stream (PES).

After packetizing the video and audio as described above,
Furthermore, packetization for transmission may be performed. MP
In the EG2 transmission system standard proposal, a transmission packet called Transport Stream (TS) is defined and transmitted as a 188-byte fixed length packet in consideration of the affinity with ATM and depacket processing.

In FIG. 7, 208 is video data 208 in which the packetized video data 205 is subdivided and TS packet headers are added. In MPEG2, each packet 208a, 208b, 208c ... Is 188.
Bytes, respectively packet headers 210a, 210
b, 210c ... Have 4 bytes. T here
Unique ID number for each data in the S packet header
It includes information necessary for depacket processing at the decoder, such as (hereinafter PID) and packet synchronization.

Next, a multiplexing process of packetized programs will be described. In FIG. 8A, the case where two programs A and B are transmitted by one transmission channel is described. The images 301 and 303 and the sounds 302 and 304 are
This is TS packetized data shown as the video data 208 or the audio data 209 in FIG. 7. Two programs A and B are video 301, audio 302, and video 30, respectively.
3 and audio 304, each program thus composed of several data is called a program in MPEG2.

FIG. 8 (b) shows an example of the structure of the multiplexer. The four types of packetized data are respectively passed through input terminals 306 to 309 to receive FIFOs (First In First Out Memory Circuit) 310 to 31.
Input to 3. Writing to the FIFO is sequentially performed as soon as a packet is generated. The status of each FIFO is input to the multiplex memory control circuit 315. Here, each FIFO is controlled so as to read the FIFO properly so that overflow or underflow does not occur, and the read FIFO output is output to the output terminal 3
The multiplexer 316 is controlled so that the signal is output to 17. When all the FIFOs underflow, the multiplex / FIFO read control circuit 315 controls so that the multiplexer 316 selects and outputs the dummy packet generated from the null packet generation circuit 314. On the other hand, if all the FIFOs overflow, it means that the data to be multiplexed exceeds the capacity of the transmission channel and cannot be multiplexed. By performing control by the multiplex memory control circuit 315 in this way, as shown in the transmission channel data 305 ((a) in the figure), high-rate video data is frequently generated and low-rate audio data is transmitted. Multiplexed at low frequency.

As described above, the digital transmission TV can transmit a plurality of programs packetized and multiplexed on one transmission channel. Therefore, in the channel selection in the current TV viewing, the transmission channel may be designated, whereas in the digital transmission TV, it is necessary to further select the program in the transmission channel.

By the way, in FIG. 8, an example in which two programs (each of which is composed of video and audio) is transmitted by one transmission channel has been described, but within the range of the transmission capacity,
In other words, the data can be combined in any way as long as the data does not overflow all the FIFOs in the figure. For example, from 7:00 to 8:00 pm, two programs, which are normal TV broadcasts consisting of video and audio, are multiplexed and transmitted, and next time from 8:00 to 9:00, normal TV broadcasts are performed. It is also possible to multiplex and transmit a program for data broadcasting such as a weather forecast and stock information together with one of the above programs. In other words, in current TV broadcasting,
The modulation frequency is a constant that is permanently invariable as long as the broadcast continues (
On the other hand, in the digital transmission TV, it is necessary to select the program in the transmission channel which changes with time even during the broadcasting. Specifically, a unique ID number (PID) is selected for each program included in the packet header 208 of FIG.

As described above, in order to enable the selection corresponding to the dynamic change of the program configuration, the program configuration table which associates the program configuration in the current transmission channel with the video / audio / data constituting each program To
It is necessary to multiplex and transmit together with data such as video and audio.

Transmission of the program structure table will be described below with reference to FIG. In the figure, reference numeral 401 is a table for associating some program composing a transmission channel with its program ID and a configuration table in the program, which is called a program association table (PAT) in MPEG2. Of the PAT described in reference (2), only the part related to the description is shown in FIG. 9 (a). The PAT is a table showing the relationship between the ID number (program number) of each program and the PID (program map PID) of the packet having the stream configuration table of the program.

The content indicated by 401 in FIG. 1A is that this transmission channel is composed of two programs 100 and 200. Further, regarding the composition contents of the programs 100 and 200, PID1000 and PID200, respectively.
0 means that the packet is transmitted. The program map table (hereinafter PM
Of T), the part relevant to the description is shown. The PMT exists for each program and is a table of streams that configure each program. As already mentioned,
PMTs of programs 100 and 200 are PIDs
It is transmitted as a packet of 1000 and PID2000, and has the contents shown in 402 and 403 of FIGS. Basically the stream type (8 bits)
, Elementary PID (13 bits), and descriptor (variable length). Reference numeral 402 denotes a video signal as a PI
The audio signal is PID = 1 as a packet of D = 1001.
This means that the program 100 is transmitted as a packet of 002 and the program 100 is composed of these two streams.
The descriptor 402c can additionally send other information such as a program name. Similarly, in 403, the video signal is a packet with PID = 2001 and the audio signal is P
This means that the packet 200 is transmitted as a packet with ID = 2002, and the program 200 is configured with these two streams. Assuming that the character strings “program A” and “program B” are transmitted to the descriptors 402c and 403c as the program names, the contents of the PAT and PMT described above are organized into a table, as shown in FIG. 9D. become.
Such a program structure table is packetized and transmitted in a fixed length like the video and audio signals described in FIG.

Next, the packet multiplexer will be described with reference to FIGS. 10 (a) and 10 (b). In the figure, the device of FIG. 8B is modified so as to correspond to the program configuration table, and the same numbers as in FIG. 8 are attached except for the modification. The multiplex memory control circuit 327 controls the FIFOs 310 to 313 to appropriately read the FIFOs so that overflows and underflows do not occur. Further, the multiplexers 324, 325, and 317 are controlled so that the output of the read FIFO is output to the output terminal 317. Further, control is performed so that the data from the table memory 319 is read within a range in which the FIFO does not cause overflow or underflow. In addition, the multiplexer 32 outputs the read data to the output terminal 317.
4, 317 are controlled. Also, the table memory 3321
The multiplexer 3 controls so as to read the data from the output terminal and outputs the read data to the output terminal 317.
25, 317 are controlled. It controls to read the data from the table memory 323. Further, the multiplexer 317 is controlled to output the read data to the output terminal 317. When all the FIFOs underflow, the multiplex memory control circuit 327 controls so that the multiplexer 326 selects and outputs the dummy packet generated from the null packet generation circuit 314. The data stored in the table memories 319 and 320 are respectively stored in the PMT generating circuit 31.
8 and 320 are data 502 and 503 which are packetized PMTs 402 and 403. The data stored in the table memory 323 is the packetized data 501 of the PAT 401 generated by the PAT generation circuit 322.

As described above, the multiplexed data 505 can be output. Next, the decoding method of the multiplexed data 505 and the program selection by the viewer will be described with reference to FIG.

In FIG. 10, the tuner 601 outputs the demodulated multiplexed data 505 (FIG. 10A). The multiplexed data 505 is FIFO 602-605, S
It is distributed and supplied to the RAM 606 and the program guide memory 607. As described above, a packet header is added to each packet of the multiplex data 505, and the header includes a unique ID number and packet synchronization for each data. The decoder reproduces the cut-out phase (break of 188 bytes) of the packet from the packet synchronization periodicity in the header by a packet synchronization circuit (not shown). Based on this phase information, the depacket controller 608 also designates the ID number included in the packet header, so that each memory (FIFO 602 to 605, SRAM
It is possible to extract and write only necessary packets in 606 and the program guide memory 607).

A fixed ID number is assigned to the PAT packet because it is indispensable for viewing selection.
In MPEG2, the ID is “0”. First, the depacket controller 608 instructs the program guide memory 607 to fetch PID “0”. Program guide memory 6
What is taken into 07 is the PA shown at 501 in FIG.
It is a packetized version of T. This PAT is bus 61
The MPU 609 reads via 0, unpacks the packet, restores the PAT indicated by 401 in FIG. 9, and stores it in the memory 611. Further, based on this PAT, the program table memory 607 is instructed to fetch two PMTs having two PIDs of 1000 and 2000, respectively. As a result, the program guide memory 607 stores 5 in FIG.
The PMTs shown in Nos. 02 and 503 are packetized. This PMT is read by the MPU 609 via the bus 610, the packet is unpacked, the PMT shown at 402 and 403 in FIG. 9 is restored, and the PMT is stored in the memory 611.

Program information by PAT and PMT is
It is displayed on the display device 615 via the VRAM 612, the D / A converter 613, and the screen synthesis circuit 614. An example of the display of the program configuration table is shown on the display device 615 of FIG.

Two program names currently being broadcast are displayed. The PID value itself does not need to be displayed because the viewer does not need to know it directly. Although it is described here that the program table memory 607 is loaded in a packetized state and the MPU 610 performs depacketing processing,
The depacket controller 608 may perform processing and instructions to write the program guide memory 607 in a depacketized state.

It is assumed that the viewer selects the program A by using the remote controller 616 from the program structure displayed as described above. The program selection instruction from the viewer is sent to the MPU 609 and the depacket controller 608 via the infrared light receiving unit 617 and the microcomputer 618. MPU609
In order to indicate that the program A has been selected, for example, by changing the color of the portion displayed as the program A in FIG. , Memory 611
Referring to the above PAT and PMT data, program A is PI
Information that D is composed of a video signal of 1001 and an audio signal of PID of 1002 is obtained and transmitted to the depacket controller 608. Depacket controller 608
Then, the FIFO 602 is controlled to depacketize and capture only the packet having the PID of 1001, and the FIFO 604 is controlled to depacketize and capture only the packet of which the PID is 1002.

In this way, the compressed video signal (203 in FIG. 7) and audio signal (204 in FIG. 7) are taken into the FIFOs 602 and 604, respectively. Further, each packet header is used in a video decoder, an audio decoder, clock reproduction, etc. as necessary (not shown). F
The video data of the IFO 602 is decompressed by the video decoder 619, and then the screen synthesis circuit 621 and the D / A converter 62.
2. Displayed on the display device 615 via the screen compositing circuit 614. The first screen compositing circuit 621 performs processing when the video signals from the two video decoders are simultaneously displayed on the screen, and the second screen compositing circuit 614 combines the video signal and the graphic data output from the VRAM 612. To synthesize. The composition of this screen composition and D / A conversion does not necessarily have to be in this order.

On the other hand, the audio signal is expanded by the audio decoder 620 and output from the speaker 625 via the selector 623 and the D / A converter 624. The processing sharing between the microcomputer 618 and the MPU 609 described with reference to FIG.
They can cover each other and can be configured with one MPU or their respective shares can be partially exchanged.

As described above, it is possible to receive a packet-multiplexed digital broadcast, select a desired program and listen to it. So far, the case where two programs A and B are transmitted through one transmission channel in the time zone of 7:00 to 8:00 pm has been described. As described above, in digital broadcasting, the program configuration in the transmission channel can be dynamically changed.

In the following, during the next time zone from 8:00 to 9:00, one ordinary TV broadcast (video signal and audio signal) and data broadcast such as weather forecast and stock information are multiplexed in the same transmission channel. In the case of transmission, a problem caused by switching of time zones will be described.

Reference numeral 801 in FIG. 12A indicates 505 in FIG.
The packet-multiplexed data shown in FIG. 2 is shown again, but the PAT and PMT packets are hatched and time is added for the sake of explanation.

As already described, the program configuration tables PAT and PMT are packet-multiplexed and transmitted at the same time as video and audio. Without this table, the viewer cannot select a program. This PAT, PMT
Must always be transmitted repeatedly. This is because it is possible to select the program by receiving the PAT and PMT without waiting too long when the reception is started. Generally, it is said that the period from when the channel is changed or when the power is turned on to when the image is played back on the screen is within a few hundred milliseconds, so if you repeatedly transmit at this interval, you can wait for a while without waiting for the program to start. Selection is possible.

By the way, let us consider a case where the user continues watching and arrives at 8:00. For PAT and PMT, 8: 00-9: 00
The program configuration for the time zone (901, 9 in FIG. 12B)
02, 903, 904) is transmitted, but PAT, PM
T is 801 to 803 in the figure transmitted over several packets after 8:00. The PAT and PMT are repeatedly transmitted from 804. As can be seen from the figure, the period 805 until the reception of the PAT and PMT is completed, and the MPU 60 for the restoration process and display thereof.
9, the program selection cannot be performed during the period required by the VRAM 612 or the like even if the viewer desires to select the program because the normal program configuration table cannot be obtained.

As described above, there is no problem in waiting a few hundred milliseconds when changing the channel or turning on the power, but during the passage of time during the reception of the program, for example, 8:00 as described above.
When PAT and PMT are changed, it is a problem that it is necessary to wait until the table reception is completed.

The above-mentioned problems do not occur only when the program structure in the transmission channel is dynamically changed. For example, even if it is always composed of two video signals and two audio signals, when one program ends and the next program starts, the PID becomes different. Therefore, it becomes necessary to receive the PAT and PMT again, and the same problem will occur until the table reception is completed.

[0033]

As described above, waiting a few milliseconds when changing channels or turning on the power is not a problem, but when PAT and PMT are changed during reception, table reception is completed. It is a problem to have to wait until you do.

Therefore, the present invention relates to switching of changing the contents of PAT and PMT (switching of programming).
It is an object of the present invention to provide a program information transmission / reception system and an apparatus for transmitting PAT and PMT prior to the start of a program corresponding to PAT and PMT so that program selective reception can be obtained smoothly.

[0035]

According to the present invention, one
When there are multiple packets of multiple program data on the transmission channel
This is a signal that is mixed and transmitted in a sequence, and the
The broadcast time of the program or the broadcast program is changed on the ket
Shows the configuration of multiple programs that are effective before
The first information table to use and the broadcast time of the program
Is a composition of multiple programs that are valid after the broadcast program has changed
Shows the packet of the second information table used for program selection.
And the first information table and
The second information table indicates the necessity of updating.
Version information and different to identify each table
When the signal with a flag is received,
The second information table and the
If the information indicates an update is required, the applicable information table
Or update the flag to release the program.
Program selection before changing the delivery time or broadcast program
Using the data of the first information table for
When the broadcast time of the program or the broadcast program is changed
In order to select a program,
The data of the information table of 2 can be used
Is.

[0036]

In the past, program selection could not be performed until all the PATs and PMTs transmitted over a plurality of packets were received and the table was completed. However, according to the above means,
The flag is received by the PAT, and at that time, the program is immediately selected by switching to the information table of the next time zone that was held.

[0037]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram shown for explaining an embodiment of the present invention, in which a PMT (program association table) and a PMT (program map table) transmitted during a time zone of 7:00 to 8:00, for example. Is shown. The PAT 101 is a PAT in the time zone 7:00 to 8:00 (401 in FIG. 9 described above) and a PAT in the time zone 8:00 to 9:00.
(901 in FIG. 12).

In this program information data, a 1-bit flag is added for each set of program number and program map PID. If this flag is 1, it means that the information data is valid in the current time zone, and if it is 0, it means that it is valid in the next time zone.

Programs 100 and 200 are from 7:00 to 8:00
The flag is set to 1 because it is a program to be broadcasted to, and the programs 300, 400, and 500 are set to 0 because it is a program to be broadcast in the next time zone from 8:00 to 9:00.
Further, PMTs corresponding to the program map PID shown in the PAT are shown in FIGS.

Also in this PMT, a 1-bit flag having the same meaning as in the PAT is added as compared with the conventional one. On the other hand, FIG. 2 shows PMTs and PMTs transmitted when the time zone is from 8:00 to 9:00. Compared to FIG. 1, the three flags 111a, 111b, 111c are set to 1, indicating that these three PMTs are currently valid. Further, the flag 0 in 111d and 111e is the PAT in the next time zone from 9:00 to 10:00.
Is shown. Similarly, PMT112-116 is also PMT11 regarding the program from 8:00 to 9:00.
Flags 4, 115, and 116 are set to 1, and the next time zone is 9:00
The PMT from ˜10: 00 transmits with the flag set to 0.

As described above, the tables PMT and PMT showing the program configurations of the current time zone and the next time zone are always provided.
Is transmitted at the same time, and a flag indicating whether it is currently valid or next valid is also transmitted at the same time.

The packet multiplex processing apparatus will be described with reference to FIG. It is assumed that this multiprocessing device multiplexes and transmits the programs on a schedule as shown in FIGS. 1 and 2, for example. Packetized video data is input to the input terminal 1028, and corresponding audio data is input to the input terminal 1029. The program 100 is input to the input terminals 1028 and 1029 from 7:00 to 8:00, and the time is from 8:
The program 300 is supplied from 00 to 9:00. Input terminal 1
Packetized video data is input to 030, and corresponding audio data is input to 1031. This input terminal 1031 has a program 200 at a time of 7:00 to 8:00.
However, the program 700 is supplied from 9:00 am to 10:00 am. It is assumed that no data is input to the input terminal 1032 during the time zone from 7:00 to 10:00. The program 400 is supplied to the input terminal 1033 from 8:00 to 9:00. The program 500 is supplied to the input terminal 1035 from 8:00 to 9:00.

Input terminals 1028, 1029, 103
0, 1031, 1032, 1033, 1035 are FIFOs 1010, 1011, 1013, 1014,
1016, 1018, 1036. FI
The outputs of the FOs 1010 and 1011 are the table memory 10
It is supplied to the multiplexer 1021 together with the 12 outputs and multiplexed. The table memory 1012 stores PMT as described later. For PMT, the current time zone P
The current time zone PMT from the MT generation circuit 1001, the next time zone PMT from the next time zone PMT generation circuit 1002, and the flag from the flag generation circuit 1003 are mixed circuits 100.
It is packetized in step 4 and supplied to the table memory 1012. A block surrounded by a broken line will be referred to as a PMT generating unit 1000a.

The outputs of the FIFOs 1013 and 1014 are supplied to the multiplexer 1 together with the output of the table memory 1015.
022 and multiplexed. Table memory 1015
Is supplied with data from the PMT generator 1000b similar to the previous PMT generator 1000a.

The output of the FIFO 1016 is connected to the multiplexer 1023 together with the output of the table memory 1017. The output of the FIFO 1018 is output together with the output of the table memory 1018 by the multiplexer 102.
4 is connected. Furthermore, the output of the FIFO 1036 is also connected to the multiplexer 1034 together with the output of the table memory 1037. Each table memory 1
017, 1019, and 1037 include PMT generator 1000.
Outputs of c, 1000d, and 1000e are supplied.

The multiplexers 1021 and 102 described above
The outputs of 2, 1023, 1024, and 1034 are further supplied to the multiplexer 1026 and multiplexed to output terminal 1
027. The multiplexer 1026 is further supplied with the output from the null packet generation circuit 1009.

Furthermore, the output of the table memory 1020 is also supplied. The table memory 1020 stores the PAT described above. That is, the data of the current time zone PAT generation circuit 1005, the next time zone PAT generation circuit 1006, and the flag generation circuit 1007 are mixed by the mixing circuit 1008 and packetized to be stored in the memory 1020.
To be supplied to. The multiplex memory control circuit 1025 controls writing / reading of the FIFO and table memory, and also controls the operation of each multiplexer.

The basic structure is the same as that described with reference to FIG. The multiplexer 1021 is open from 7:00 am
Program 100 at 8:00, program 300 at time 8:00 to 9:00, program 60 at time 9:00 to 10:00
0 shall be multiplexed. Multiplexer 1
022 multiplexes the program 200 during the time zone 7:00 to 8:00 and the program 700 during the time zone 9:00 to 10:00. The multiplexer 1023 multiplexes the program 400 in the time zone from 8:00 to 9:00. The multiplexer 1024 multiplexes the program 500 in the time zone from 8:00 to 9:00. The multiplex memory control circuit 1025 and each multiplexer operate in the same manner as in FIG.

As described above, the programs processed by the multiplexers for each time zone are summarized as shown in FIG. On the other hand, in the current time zone PMT generation circuit 1001, the program 100 is in the time zone 7:00 to 8:00, and the time is 8:00 to 9:00.
To the program 300, and the PMT related to the program 600 in the time zone 9:00 to 10:00. Next time zone PMT
The generation circuit 1002 generates the PMT for the program 300 during the time zone 7:00 to 8:00 and the PMT for the program 600 during the time zone 8:00 to 9:00. In the flag generation circuit 1003,
The table generated from the current time zone PMT generation circuit 1001 is added with 1 and the table generated from the next time zone PMT generation circuit 1002 is added with 0 as a flag, and the mixing circuit 10 is added.
It mixes and packetizes by 04, and it writes in the table memory 1012 as PMT. Table memory 1012
Will be written in PMT10 between 7:00 and 8:00
2 (FIG. 1), the PMT 114 (FIG. 2) during the time zone 8:00 to 9:00. Below, each table memory 10 for each time zone
The PMTs stored in 12 are summarized as shown in FIG. Therefore, although not shown, the PAT generator,
Time information is input to each PMT generator, and time information is also given to the multiplex memory control circuit 1025.

As described above, the table memory has the total number of programs in the current time zone and the next time zone, and the PMT in the current time zone is multiplexed with the video and audio of the program by the same multiplexer, The time zone PMT is sent to the free multiplexer. As described above, it becomes possible to transmit the PMT and PMT as described with reference to FIGS.

Next, the processing of the PMT and the receiving side of the PMT will be described. The configuration of the receiver itself is shown in FIG.
However, the processing procedure by the MPU 609 is different from the conventional example.

The processing on the receiving side will be described with reference to the flowcharts shown in FIGS. 5 and 6 and FIG. Time zone
It is assumed that the receiver is turned on between 7:00 and 8:00. As in the conventional example, the depacket controller 608 sets the PID
The program table memory 607 is instructed to fetch "0" (step 1101). Program table memory 60
What is taken in 7 is a packetized version of the PAT shown at 101 in FIG. This PAT is read by the MPU 609 via the bus 601, unpacks the packet, and
The PAT indicated by 101 is restored and stored in the memory 611 (step 1102). Furthermore, based on this PAT,
Depacket controller 60 to take in 5 PMTs with PIDs of 1000, 2000, 3000, 4000 and 5000 respectively
8 (step 1103). As a result, what is stored in the program table memory 607 is 102-in FIG.
The PMT shown in 106 is packetized. This PMT is read by the MPU 609 via the bus 601, the packet is unpacked, and P shown in 102 to 106 in FIG.
MT is restored and stored in the memory 611 (step 110).
4). In this way, PMT, PMT and the fetched program configuration table are obtained.

Program information by PAT and PMT is
VRAM 612, D / A converter 613, screen composition 6
It is displayed on the display device 615 via 14. At this time, referring to the PAT and PMT flags, the flag is 1,
That is, it is possible to display the two program names currently being broadcast by using only the table indicating that the programs are currently valid. It is assumed that the viewer selects the program A using the remote controller 616 based on the program structure displayed in this manner. The viewer receives a program selection instruction from the infrared light receiving unit 617,
It is sent to the MPU 609 and the depacket controller 608 via the microcomputer 618. The MPU 609 performs a process of feeding back the remote control operation by the viewer to the screen, for example, by changing the color of the portion displayed as the program A so as to indicate that the program A is selected, and the memory By referring to PAT and PMT on 611, information that the program A is composed of a video signal with PID 1001 and an audio signal with PID 1002 is obtained,
Notify the depacket controller 608. The depacket controller 608 controls the FIFO 602 to depacketize and capture only the packet having the PID of 1001, and controls the FIFO 604 to depacketize and capture only the packet having the PID of 1002. In this way, the FIFOs 602 and 604 respectively have
The compressed video signal (eg, 303 in FIG. 8) and audio signal (304 in FIG. 8) are captured. Further, each packet header is used in a video decoder, an audio decoder, clock reproduction, etc. as necessary (not shown).

The video data of the FIFO 602 is decompressed by the video decoder 619, and the screen synthesis circuit 621, D / A
Display device 6 via converter 622 and screen synthesis circuit 614
15 is displayed. The first screen synthesis circuit 621 has 2
When the video signals from the two video decoders are simultaneously displayed on the screen, the processing is performed, and the second screen synthesis circuit 614 is executed.
Synthesizes the video signal and the graphic data output from the VRAM 612. The configuration of this screen composition and digital-analog conversion does not necessarily have to be this configuration in this order.

On the other hand, the audio signal is expanded by the audio decoder 620 and output from the speaker 625 via the selector 623 and the D / A converter 624. The microcomputer 61
8 and the MPU 609 can cover each other, and can be configured by one MPU, or the respective shares can be partially exchanged.

As described above, it is possible to receive a packet-multiplexed digital broadcast, select a desired program, and listen to it. At 8:00, it is assumed that PMT and PMT are changed. As shown in FIG. 5 and FIG. 6, PMT, PM
Regarding T, it is constantly checked whether an update is necessary (step 1105). MPEG2 PMT, P
MT has a 5-bit field called a version number, and this check is possible. If the update is necessary, the PAT is fetched in the same manner as steps 1101 and 1102 (steps 1106 and 1107). At this time, the PAT 111 shown in FIG. 2 is captured. If the viewer is not trying to select a program (step 1108), there is no problem, so step 110
Import PMT in the same manner as 3 and 1104 (Step 11
09, 1110), and the process is returned to step 1105.
At this time, the PAT 112 shown in FIG.
116. If the viewer is going to select a program (step 1108), the PMT is not fetched and the PAT 111 and PMT (102 to 106 in FIG. 1) currently stored in the memory 611 are referred to. PAT1
11, the programs currently being broadcast are 300, 400,
500, and each PMT has a PID of 3000, 4000,
Since it is known to be 5000, PMT 104, 105,
See 106. That is, the flag of the PAT 111 is checked, and only the portion where the flag is 1, that is, the flag currently valid is referred to.

When PMT and PMT are updated and stored in the memory 611 (steps 1107 and 111)
It is also possible to refer to the flag in 0) and update only the flag itself and the table indicating that the flag is 0, that is, the flag is valid next time. In this case, PM
The respective flags of T and PMT are referred to.

As the program information, it is conceivable to transmit a program table for a relatively long period of time like a television guide for several weeks or one month which is currently sold as a magazine. Such a TV guide-like program table is a program table in the sense of announcing / planning of future broadcasts, and the PAT and PMT according to the present invention transmit the program structure being broadcast and are used for program selection processing at the receiver. Essentially different in the sense of being essential.

In the above description, the flag is used to allow the PAT or PMT to distinguish between the currently effective program information and the next effective program information. As one example of this flag, 1 bit is prepared next to the program map PID and this bit is used. However, according to the present invention, this flag position is not limited to the above example, but may be inserted and transmitted and received in a portion having a margin in accordance with the arrangement on the transmitting and receiving side. In the above explanation, PA
Although T and PMT are said to be always sent in the current time zone and the next time zone, for example, when the program schedule is switched, the time point is set as Sakai, and the PA in the constant time next time zone is set.
T and PMT may be transmitted so as to overlap those of the current time zone. Further, in the above description, the program organization is used as a combination state of a plurality of programs transmitted on the same channel, but as a case where the program organization is changed, one program (program) is used.
Since there are various forms such as only changing and other programs not changing, or changing all at the same time, they are collectively referred to as the program structure.

[0060]

As described above, according to the present invention, the table (PAT, PAT) relating to the currently broadcast program is displayed.
MT) and the table of programs to be broadcast in the next time period are overlapped and sent, so that even when the contents of PMT and PMT are changed, programs can be selected before PMT and PMT reception is completed.

[Brief description of drawings]

FIG. 1 is a diagram shown for explaining a PMT and a transmission mode of a PMT according to an embodiment of the present invention.

FIG. 2 is likewise a PMT and P in one embodiment of the present invention.
The figure shown in order to demonstrate the transmission form of MT.

FIG. 3 is a diagram showing a packet multiplexer according to an embodiment of the present invention.

FIG. 4 is an explanatory view shown for explaining an operation example of the apparatus of FIG.

FIG. 5 is a flowchart shown to explain the operation of the receiving apparatus according to the present invention.

FIG. 6 is a flowchart shown to explain the operation of the receiving apparatus according to the present invention.

FIG. 7 is a diagram shown for explaining a compression technique of MPEG2.

FIG. 8 is a diagram shown for explaining the principle of packet multiplexing.

FIG. 9 is an explanatory diagram of a packet association table (PAT) and a program map table (PMT) transmitted in packet multiplexing.

FIG. 10 is a diagram shown for explaining a packet multiplexer.

FIG. 11 is a diagram showing a receiving device for receiving a packet-multiplexed signal.

FIG. 12 is an explanatory diagram shown for explaining a problem of a conventional packet multiplexed signal transmission method.

[Explanation of symbols]

1010, 1011, 1013, 1014, 1016,
1018, 1034 ... FIFO, 1012, 1015,
1017, 1019, 1037, 1020 ... Table memory, 1001, 1005 ... Current time zone PAT generation circuit,
1002, 1006 ... Next time zone PAT generation circuit, 100
3, 1007 ... Flag generation circuit, 1004, 1008 ...
Mixing circuit, 1025 ... Multiplex memory control circuit, 1009 ... Null packet generating circuit, 1021, 10
22, 1023, 1024, 1034, 1026 ... Multiplexers.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Natsuki Odairo 8 Shinsita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture, Multi-Technology Research Laboratory, Toshiba Corp. (72) Inventor, Eiichiro Tomonaga 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Address: Toshiba Multi-Dia Technology Laboratory Co., Ltd. (56) Reference JP-A-4-95480 (JP, A) JP-A-3-143085 (JP, A) JP-A-6-124502 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N ^7/ 00-7/088 H04N 5/38-5/46 JISST file (JOIS)

Claims (4)

(57) [Claims] 1. A plurality of program data on one transmission channel.
Signal that multiple packets of data are mixed and transmitted in time series
Therefore, the plurality of packets include the broadcast time zone of the program.
Or the composition of multiple programs that are valid before the broadcast program is changed.
The first information table used for program selection,
Available after the broadcast time zone or broadcast program of the group has changed
It shows the composition of multiple effective programs and is used for program selection.
And an information table packet, and
The first information table and the second information table contain
The version information indicating the necessity of updating and each table
The signal with different flags for identification
Is received, the first and second information tables are stored in the memory, and the version information indicates that update is required, the corresponding
Before updating the information table or the flag described above, the broadcast time zone of the program or the broadcast program is changed
Is the data of the first information table for program selection.
, The broadcast time zone of the program or the broadcast program was changed
In case the program was sent in advance for program selection
The data in the second information table can now be used.
A program information receiving method characterized by the following . 2. The first and second information tables are ISO /
Program association defined by IEC1318 standard
It is a table based on the online table (PAT)
The program information receiving method according to claim 1 . 3. The program data is compressed by the MEPG method.
The method according to claim 1, further comprising video data . 4. A plurality of program data on one transmission channel.
Data that is transmitted by mixing multiple packets in time series.
And the plurality of packets includes the broadcast time zone of the program.
Or, if there are multiple valid programs before the broadcast program is changed,
A first information table showing a configuration and used for program selection,
After the broadcast time of the program or the broadcast program has changed
A second configuration used for program selection, showing the configuration of a plurality of effective programs
And the information table packet of
The first information table and the second information table contain
Version information indicating whether update is required and each table
The flag with a different flag to identify
Means for receiving a number and a means for storing the first and second information tables in a memory.
And the version information indicates that update is required,
Information table or update the flag
Means and before the broadcast time zone or broadcast program of the program is changed
Is the data of the first information table for program selection.
The means to use and the broadcast time zone or broadcast program of the program has changed
In case the program was sent in advance for program selection
The data in the second information table can now be used.
A program information receiving apparatus comprising: